Process for the preparation of a catalyst system, catalyst system, and its use for the production of a cast polyamide

Abstract

A process for the production of a catalyst system is described. For this purpose, at least one alkali metal alcoholate is introduced into a lactam melt and the resulting alcohol is removed. The resulting catalyst system is used for the production of cast nylon.

1 . A process for preparing a catalyst system by reacting at least one lactam with at least one alkali metal alcoholate, the process comprising:
 a) heating at least one lactam to obtain a lactam melt;   b) introducing to the lactam melt at least one alkali metal alcoholate selected from alkali metal methanolate and alkali metal ethanolate into the lactam melt; and   c) removing from the lactam melt alcohol formed during the process;   wherein the amount of the alkali metal ethanolate is between 50 and 100% by weight relative to the total amount of alkali metal alcoholate.   
     
     
         2 . Process The process according to  claim 1 , wherein the amount of alkali metal ethanolate is between 70 and 100% by weight relative to the total amount of alkali metal alcoholate. 
     
     
         3 . Process The process according to  claim 1 , wherein the alkali metal alcoholate is the alkali metal ethanolate. 
     
     
         4 . The process according to  claim 1 , wherein the at least one lactam is selected from β-lactam, γ-lactam, δ-lactam, ε-lactam and lauric lactam. 
     
     
         5 . The process according to  claim 1 , wherein the at least one alkali metal alcoholate is selected from sodium alcoholate, lithium alcoholate and potassium alcoholate. 
     
     
         6 . The process according to  claim 5 , wherein the lactam is ε-lactam. 
     
     
         7 . The process according to  claim 1 , wherein the at least one alkali metal alcoholate is sodium ethanolate. 
     
     
         8 . The process according to  claim 1 , wherein the catalyst system obtained has a residual alcohol content of 0.3% by weight or less based on the total amount of the catalyst system. 
     
     
         9 . The process according to  claim 1 , wherein the process further comprises finishing the catalyst system. 
     
     
         10 . A catalyst system obtainable by the process according to  claim 1 . 
     
     
         11 . The catalyst system according to  claim 10 , wherein the catalyst system has a residual alcohol content of 0.3% by weight or less. 
     
     
         12 . The catalyst system according to  claim 11 , wherein the amount of alkali metal lactamate is between 8 and 28% by weight based on the total amount of the catalyst system. 
     
     
         13 . The catalyst system according to  claim 10 , wherein the alkali metal lactamate is selected from lithium lactamate, sodium lactamate and potassium lactamate. 
     
     
         14 . The catalyst system according to  claim 10 , wherein the lactam is selected from β-lactam, γ-lactam, δ-lactam, ε-lactam and lauric lactam. 
     
     
         15 . A polyamide prepared according to the process of  claim 1 , the process further comprising polymerizing the lactam melt into a polyamide. 
     
     
         16 . The polyamide of  claim 15 , the process further comprising casting the polyamide into a cast polyamide. 
     
     
         17 . The polyamide of  claim 15 , wherein the polyamide has a residual alcohol content of not more than 0.3% by weight. 
     
     
         18 . The catalyst system of  claim 11 , wherein the catalyst system is essentially free of water-insoluble solids. 
     
     
         19 . The catalyst system of  claim 11  in the form of a melt. 
     
     
         20 . The catalyst system of  claim 11  in the form of a solid.